1. Field of the Invention
This invention relates to an improved method for the tensile testing of metal foil specimens and to an aligning apparatus for use in the method.
2. Description of the Prior Art
In the strength of material testing of any specimen the ultimate goal is the acquisition of accurate and reproducible results. The achievement of this goal in the testing of thin metal foil specimens, however, has proved very difficult for more often than not, the results of the testing have been erratic and unreliable. Moreover, the severity of the problem has increased in recent years since advances in structural design are permitting the use of thinner metal coverings useful, for instance, as rocket booster skins. The extreme surface to volume ratio of these thin foils has only aggravated the problem and made achievement of consistent and accurate tensile values all the more difficult.
Numerous techniques have been advanced in the prior art as solutions to these problems. None, unfortunately, have proved completely satisfactory.